Porcupine caribou
The Porcupine caribou or Grant's caribou is a subspecies of the reindeer found in Alaska, United States, and adjacent parts of Canada. It resembles the subspecies known as the barren-ground caribou and is sometimes included in it.
Migratory caribou herds are named after their birthing grounds, in this case the Porcupine River, which runs through a large part of the range of the Porcupine herd. Though numbers fluctuate, the herd comprises about 218,000 animals. They migrate over a year between their winter range and calving grounds at the Beaufort Sea, the longest land migration route of any land mammal on Earth. Their range spans the Alaska/Yukon border and is a valued resource cooperatively managed by the Alaska Department of Fish and Game, Canadian wildlife agencies and local aboriginal peoples. The caribou are the primary sustenance of the Gwichʼin, a First Nations/Alaska Native people, who traditionally built their communities to align with the caribou's migration patterns. They are also routinely hunted by other indigenous peoples, including the Inupiat, the Inuvialuit, the Hän and the Northern Tutchone.
By July 2017, the Porcupine herd had reached a record high of about 202,000 to 235,000 animals. Sixteen years earlier, in 2001 the same herd was only half as large. While other barren-ground caribou herds have declined by 90%, the Porcupine herd has remained relatively stable.
Taxonomy
The Porcupine caribou, also known as Grant's caribou, is a subspecies of the caribou found in Alaska, United States and adjacent parts of Canada. It is sometimes included in the subspecies called the barren-ground caribou, which it resembles.Range
The Porcupine herd range covers migrating annually from the calving grounds and birthing grounds, the Porcupine River after which they are named, to "the river valleys and slopes in the Ogilvie and Richardson Mountains in the Yukon and the southern Brooks Range in Alaska in the winter. The calving area is located on in the Porcupine River coastal region of the Beaufort Sea known as the 1002 area, which is part of the Arctic National Wildlife Refuge. The area runs through a large part of the range of the Porcupine herd.In the spring the pregnant cows move "northeast from the Alaskan winter ranges or north and northwest from the Canadian winter ranges. If snowmelt is early, they will then move westward along the north slope of the Brooks Range into Alaska."
calving grounds, 1983–2001 Most Porcupine caribou calves are born in the first week of June and they are at their most vulnerable from their primary predators on the calving ground - golden eagles, grizzly bears and wolves - during the first three weeks when they are dependent on milk from their mothers. About one quarter of them die during this period. Their annual land migration between their winter range in the boreal forests of Alaska and northwest Canada over the mountains to the coastal plain and their calving grounds on the Beaufort Sea coastal plain, is the longest of any land mammal on earth.
Management
The Alaska Department of Fish and Game, Canadian wildlife agencies, and local aboriginal peoples cooperatively manage the Porcupine herd. The Porcupine Caribou Management Board advisory board was established under the Porcupine Caribou Management Agreement in 1985, whose members include representatives from the Gwich'in Tribal Council, Na-cho Nyäk Dün, Vuntut Gwitchin, Government of Yukon, Tr'ondëk Hwëch'in, Inuvialuit Game Council, and the Government of Canada. The PCMB publish an annual Porcupine Caribou Harvest Report. In their February 2018 report they recorded that a 2017 photocensus estimated a mean of 218,457 caribou caribou, indicative of an increasing trend from 2010 to 2017, from 169,000 to about 218,000. On July 17, 1987, the United States and the Canadian government signed the "Agreement on the Conservation of the Porcupine Caribou Herd" a treaty designed to protect the subspecies from damage to its habitat and migration routes. Both the Ivvavik National Park and Vuntut National Park border the ANWR. The treaty required an impact assessment and required that where activity in one country is "likely to cause significant long-term adverse impact on the Porcupine Caribou Herd or its habitat, the other Party will be notified and given an opportunity to consult prior to final decision". This focus on the Porcupine caribou led to the animal becoming a visual rhetoric or symbol of the drilling issue much in the same way the polar bear has become the symbol of global warming.Potential threats to the Porcupine herd
Climate change and the increased frequency of extreme weather events, such as unprecedented late slow melting, negatively affect the Porcupine herd. As a result there was "very high early calf mortality." The primary predators for calves are golden eagles, grizzly bears and wolves. "Caribou exposed to industrial development shift away from the pipelines and roads." The passage of the provision opening ANWR's 1002 to oil and gas drilling is considered to be a threat. In 2001, some biologists feared development in the Refuge would "push caribou into the foothills, where calves would be more prone to predation." In their 2005 report, Russell and McNeil reiterated concerns that new calving areas would make the herd more vulnerable, as area 1002 provides a much higher quality of diet conditions than the alternatives in Canada.Indigenous peoples
The Porcupine caribou are a valued resource as primary sustenance to indigenous peoples in Alaska and northern Canada. Gwichʼin, a First Nations/Alaska Native people traditionally built their communities to align with the caribou's migration patterns. The Inupiat, the Inuvialuit, the Hän and the Northern Tutchone also hunt caribou from this herd on a regular basis.Arctic National Wildlife Refuge
The Arctic National Wildlife Refuge covers of the northern Alaskan coast, in northeast Alaska between the Beaufort Sea to the north, Brooks Range to the south and Prudhoe Bay to the west. It is the largest protected wilderness in the United States and was created by Congress under the Alaska National Interest Lands Conservation Act of 1980.with The National Petroleum Reserve to the West, the Arctic National Wildlife Refuge with area 1002 to the east. On December 22, 2017, President Donald Trump signed the Tax Cuts and Jobs Act of 2017, a provision that opened the 1002 area of ANWR to oil and gas drilling, into law. The Act contains provisions that would open 1.5million acres in the Arctic National Wildlife Refuge to oil and gas drilling. Opening the Arctic Refuge to drilling "unleashed a torrent of opposition from conservationists and scientists." Democrats and environmentalist groups such as the Wilderness Society criticized the Republican effort. Since 1977 area 1002, which encompasses much of the Porcupine caribou calving grounds, has been a topic of controversy. The subsection on the coastal plain, known as the "1002 area" is located between the Brooks Range and the Beaufort Sea. The plain "stretches west from the Yukon border more than a hundred miles, a flat expanse of tundra laced with tussock wetlands and braided rivers."
Herd size
Unlike many other Rangifer tarandus subspecies and their ecotypes, the Porcupine herd is stable at relatively high numbers. Some barren-ground caribou herds have "declined more than 90 per cent from historic averages", causing the Committee on the Status of Endangered Wildlife in Canada, to sound the alarm.According to an aerial count reported in July 2017, the size of the Porcupine herd had increased to "between 202,000 and 235,000 animals, nearly twice the number of animals recorded at a low point in 2001.
A previous peak population occurred in 1989 with 178,000 animals and was followed by a decline by 2001 to 123,000. A recovery was observed in 2010 with an increase to 169,000 animals.